The present invention relates to an electromagnetic actuator device according to the preamble of the main claim.
The present invention further relates to a use of such an electromagnetic actuator device.
Electromagnetic actuator devices, in which an armature unit which is configured in the manner of a tappet and which is able to be driven as a reaction to the energising of stationary coil means is guided in an axial direction so as to be able to be moved out of an actuator housing, are generally known from the prior art and are used for very different actuating tasks, in particular also in a motor vehicle context.
In this case, for example, a use of such actuators for actuating the camshaft of an internal combustion engine has proved to be an advantageous use; generic actuators in which, for example, permanent magnets on the armature side cooperate in a repelling manner with the (energised) coil means are characterised by brief switching times (thus high switching dynamics) and robustness and reliability in operation, are also suitable for inexpensive mass production.
However, the disclosed application of actuating a camshaft generally requires more than one actuator unit; the armature tappet engaging in a controlled manner in a shifting groove (groove track) of a camshaft for actuating purposes generally requires at least one second tappet to be provided, generally adjacent thereto, in order to be able to effect, in addition to a first movement, a second opposing movement of the camshaft.
This technology is generally known per se and is used in the mass production of motor vehicles. With regard to an arrangement of a plurality of armature tappets, in this case it is known, on the one hand, to provide these tappets (as the respective armature tappets) in a common housing adjacent to one another and to operate them in a suitable manner.
However, this leads to large housing dimensions when minimum (engagement) spacings of the tappet ends have to be ensured. Such large housings are in turn problematical when installed in the restricted space conditions on the engine block. Moreover, such an arrangement is problematical with regard to assembly tolerances and/or operating tolerances which are unavoidable on a motor vehicle internal combustion engine, since when the tappets are repeatedly guided in a common housing this generally does not allow for any tolerance compensation as might be necessary, for example, in the case of thermally-induced fitting problems during installation, for example.
However, the use of two or more separate actuator units not only entails an additional cost for the assembly and anchoring of each individual associated actuator housing, but each of these actuator units also has to be electrically connected and wired separately, so that the structural and the assembly cost is also increased here.